由于气候变化和人类活动的影响，东江流域的洪水序列可能产生了变异。为了揭示多尺度洪水序列时空变异规律，利用水文变异诊断系统对东江流域主河道的龙川、河源、岭下、博罗4个控制站的年最大一、三、五、七日洪水序列进行变异诊断。结合东江流域内降雨序列的变异情况、水利工程设施等气候和人类活动影响因素的分析，揭示了洪水变异的物理成因。结果表明：龙川、河源、岭下、博罗各站的年最大一、三、五、七日洪水序列均发生了不同程度的变异。通过对各洪水序列的空间变异关系分析，发现对于不同洪水序列，各站之间的联系密切程度不同。物理成因分析表明：东江流域洪水变异主要是受梯级水电站修建的影响，受气候变化影响较小。 Under the influence of climate change and human activities, alterations may happen to the distri-bution regulations and parameters of flood series in the East River basin. In order to uncover the multi-scale flood series alterations on temporal and spatial scales, annual maximum 1-day, 3-day, 5-day and 7-day floods of the Longchuan, Heyuan, Lingxia and Bolo stations in the East River basin were chosen, then the hydro-logical alteration diagnosis system was used to analyze the alteration. Combining with the analysis of the in-fluence of climate change and human activities such as the alteration of precipitation series and water con-servancy facilities in the East River basin, the physical causes of flood alteration are mainly due to the cas-cade hydropower plants. Results indicate that the variation degree of annual maximum 1-day, 3-day, 5-day and 7-day floods at the Longchuan, Heyuan, Lingxia, and Bolo stations are different. It is shown that the re-lationship between stations is different and the influence of climate change is very little